The present invention relates to a method of making optical coupling devices.
The present invention relates to a method of making optical coupling devices used in light coupling arrangements for arc sources with relatively long arc gaps (e.g., 7 mm) that are not as xe2x80x9cpoint-likexe2x80x9d as shorter gaps (e.g., 2.7 mm). These devices, described in detail in the above-cross-referenced application, employ non-focusing optical devices to achieve a reduction in the angular distribution of light transmitted from a light source to the extent desirable for efficient collection and transmission by a light guide or fiber arrangements. This enables the light to be coupled at high efficiency between the light source and one or more light guides or optical fibers. While conventional optical reflecting elements (e.g. elliptical reflectors) made from vitreous materials can be typically formed by pressing molten gobs of vitreous material, the nearness of the hot arc source to the reflecting surface of these elements necessitate the use of highly refractive vitreous materials for their manufacturexe2x80x94e.g., quartz. These materials, however, are difficult and expensive to form by pressing.
It would be desirable if the optical devices of the light coupling arrangements described in the above cross-referenced application could be manufactured more easily and at lower costs than elliptical (or other focusing) collectors.
In accordance with an exemplary embodiment of the invention, a method of making an optical device comprises the steps of providing a body of vitreous material that is generally tubular along an axis. A portion of the body is molded with external mold structure for forming a bulbous region when the interior of the tube is pressurized. An axial portion is cut from the bulbous region to form a first coupling device with first and second axially oriented openings.
The foregoing method can produce optical coupling devices with excellent optical quality in an economical manner that can be used, for instance, in the light coupling arrangements of the above cross-referenced application.